Automatic screw-machine.



H. B. LESTER.

AUTOMATIC SCREW MAUHINE.

APPLIOATIQN FILED SEPT. 25, 1901.

Patented Mar. 30, 1909.

14 SHEBTS--SHEET 1.

A uvvnvrom- H. B. LESTER.

AUTOMATIC SCREW MACHINE.

APPLICATION FILED 8BPT.25,1907. 91 ,4 1 Patented Mar. 30, 1909.

14 SHEETS-SHEET 2,

mN Q Ni M w mwkw Am Q\ H. B. LESTER.

AUTOMATIC sonnw MACHINE. APPLICATION FILED SEPT. 25,

1m Patented Mar 30,1909.

H. B. LESTER.

AUTOMATIC SCREW MACHINE.

APPLIUATION FILED SEPT. 25,

Patented Mar. 30, 1909.

14 SHEBTS-HHEBT 5.

l ITNEXSBSU 42am H. B. LESTER.

AUTOMATIC somzw MACHINE.

APPLIUATION FILED SEPT.25,190T. 91 6,461 Patented Mar. 30, 1909.

14 SHEETS-SHEET 6.

Haj

/44 N Am- -YVITNESSES: IN VEN TOR M:- H/w/M By 7 Clara H. B.'LESTER.

AUTOMATIC SGREW MACHINE.

APPLICATION FILED SEPT. 25, 1907.

Patented Mar. 30, 1909.

INVENTOR.

A TTORNE)".

H. B. LESTER.

AUTOMATIC soanw MAUHINE.

APPLIOATION FILED SEPT, 26, 1907 91 6,461 Patented Mar. 30, 1909.

14 SHDETS SHEIIT 8 0, 5 p d ll/lllll H. B. LESTER.

AUTOMATIC SGEEW MACHINE.

APPLIEIATION FILED SEPT25, 1907.

Patented Mar. 80, 1909 14 BHEETSSHEET 9,

zwmzz-am ATTORNEY H. B. LESTER.

AUTOMATIC SUREW MACHINE.

APPLIOATION FILED mm. 25, 190?,

Patented Mar. 30, 1909.

14 SHEIITS-SHEET 10 INVENTOK 4M 1 V/ T N 15 5855 (7 TTORNEY.

H. B. LESTER.

AUTOMATIG SGREW MACHINE.

' AFPLIUATION FILED SBPT.25,1907. 916,461, Patented Mar. 30, 1909 14; EHEBTB-$HEET 11v WITNESSES: INVENTOR 664% 3 6 WWW H. B. LESTER AUTOMATIC SCREW MACHINE.

APPLIOATION FILED SEPI225,19(W.

Patented Mar. 30, 1909.

14 SHEETB- SHEET 12 H. B. LESTER.

AUTUMATIU SCREW MACHINE APPLICATION FILED SEPT, 20, 190?.

9 1 6,46 1 Patented Mar. 30, 1909 WITNESES: IN VENTUR $1 M 5; Lw;j

A TTQRNE E P 7 Ew N1 I! -w RAT. B W TWB B HEW w n mn m um mm m AP A 14 SHEETB-SHEET M.

//VV/VTO/?. WW XKMZ ATTORNEY:

UNITED sTA Es PATENT OFFICE.

HARRY B. LESTER, O1" DAYTON, OlllO, ASSIGNOR TO THE DAVIS EW1NG MACHINE COMPANY, OF DAYTON, OHIO A CORPORATION OF OHIO.

AUTOMATIC SCRE W-MACHIH E Specification of Letters Patent.

Patented March 30, 1909.

Application filed September 25, 1907. Serial No. 994:,618.

To (ill whom it may concern:

Be it known that I, l-lAmn' B. LES'IER, a

citizen of the United States, residing at Dayton, in the county of Montgomery and State of Ohio, have invented a. new and use ful Automatic Screw-Machine, of which the following is a specification.

This invention relates to an automatic screw machine of the multiple, tubularspindle, rod feed ty e, with central drive having tubular spind es that are always rotated in the same direction for causing the rods to be operated upon by the tools, and which can be detained in their respective stations and caused to feed the rods collectively to the same or different tools for producing the same or d1 fierent cuts on the several rods, or, the spindles can be iven intermittent revolutionary'inovements w iereby the rods may be presented to a less number, the same number, or a greater number of tools than there are spindles for producing various progressive cuts of the desired character upon the several rods.

The object of the invention is to produce a simple, compact and eflicient machine of this character having new and important combinations of elements which give it wide range of action, great certainty 1n the auto matic operation of the parts, close accuracy of the product, complete accessibilit to the working mechanism and great faci ity for adjusting and making changes from one piece of work to another without requiring new tools.

The machine which is illustrated is so designed that three rods of stock may be fed co lectively, each to its own tool and no other, which tools may be the same or a different. character, and which at each revolution will produce the same cut on each rod, or the machine can be operated, so that the several rods held by the several spindles may be successively presented to the same number-of or to double the number of different tools for producing difi'erent or successive cuts upon each rod, whereby a large number of sim )le pieces or a smaller number of complicat pieces, that is, pieces having a variety of cuts, can be rapidly produced, on a machine that is comparatively cheap to build, very easy to adjust, and can be operated by an unskilled mechanic accurately and, without liability of disturbing the proper adjustment or danger of damage to the essential parts.

Figure 1 of the acconnanying drawings shows a side elevation oi the spindle head end of the machine with the frame cut away to show an end view of the crossslide mechanism. Fig. 2 shows a central vertical section of the spindle head end of the machine. Fig. 3 shows a side elevation of the tool head end of the machine. Fig. 4 shows a central vertical section of the tool head end of the machine. Fig. 5 shows an elevation of the left hand end of the machine. Fig. (5 shows a central section of the spindle head rotating pinion and the mechanism for putting it into and out of action.

.Fig. 7 shows the lever that is acted upon by the cam for starting and stopping the spindle head rotating movement. Fig. 8 shows the ratchet, pawls and spring by which'the continuous motion of the driving pulley is intermittently transmitted to the spindle head rotating pinion. Fig. 9 shows a pawl. Fig. 10 shows a central section of a mechanism for producing the intermittent rotation of the spindle head, which is somewhat simpler than that shown in Fl 6. Fig. 11' shows end and side views 0 the sliding sleeve with the pawls and cam sur- Faces formed inte ral withit. Fig.12 is a. transverse vertica section of the machine on the plane indicated by the dotted line 12-12 on Fig. 2, showing the spindle head indexing bolt and its operating cams, also cutting through the gear chamber and showing the driving gears. Fig. 13 is a similar section on the plane indicated by the dotted line l3-13 on Fig. 2, showing the spindle head rotating pinion and ear, and the chucking lever cam and'cam s iaft actuating mechanism. Fig. 14 shows the chuck look ing sleeve b means of which all the chucks maybe 1112 e to operate coincidently. Fig. 15 is a verticahtransverse section on the plane indicated by the dotted line 15-15 on Fig. 2, showin r the meansjzmployed to operate the radial tool usually employed for forming or cuttin 011' the rod held by the uppermost siind e. Fig. 16 shows a section of the ra ial tool holder slide and its immediate operating mechanism. Fig. 17 shows an elevation looking at the right hand end of the spindle head of the machine with all three cutting off or forming tools in operative position. Fi 18 shows an elevation of the right han end of the tool head. Fig. 19 is a vertical transverse section of the tool. head on the lane indicated by the dotted line 19--l9 on the die drivin gears and the oscillating shaft gear, and lead cam. Fig. 20 shows top and end views of the die gear mechanism. Fi 21 shows an elevation of the left hand on of the tool head. Fig. 22 shows a central ion itudinal section on. larger scale of one of the die spindles and its r0- tating mechanism. Fig. 23 shows the same die spindle arranged for holding a nonrotating tool. Fig. 24 shows the die spindle threading clutch. Fig. 25 is a view of the tool spindle connectin collar. Fig. 26 shows another view of the ever that is acted upon by the cam for starting and stopping the spindle head rotating movement. 1g. 27 is a perspective view of the tool head 1' ciprocating rack and a removable cam and its hub, that are employed to reciprocate the rack. Fi 28 shows develo ments of the cams user to give different engths of feed to the tool head and feed tube.

In the machine illustrated there are three rod spindles with red feeds and chucks and there are three transversely movable cutting tools and means'for usin six axially movable tools, two of the latter ein shown as threading tools. It is to be on erstood however, that the invention is not limited to the exact number of spindles shown and also that the number of tools may be increased or diminished according to the number of spindles.

The spindle head 1 is rotatably supported at its ends by bearings 2 in the frame. Encircling the spindle head and forming the wearing surface at the left hand end is a sleeve 3 that is drawn to place by screws 4, whereby all end motion of the spindle head resulting from wear can be taken up. Fig. 2.

In each spindle, of which three are shown,

- is a feed tube 5 with a split gri ping collct a ilot shaft 12. Fi

6 at one end and a rooved col ar 7 at the other end. The fee tubes are moved back and forth at the proper time by the engagement with the grooved collars of either one or three of the rolls 8, which are fastened to the roll disk 9 according to whether the tubes are to he reciprocated singly in su cession or simultaneously. This disk is fastened to a reciprocating shaft 10 that tends through the center of the spindle head and also through the center of the tool head to the right hand end of the machine where it is connected with an arm 11 supported by gs. 1, 2, 3,4. A rod 13 ustably attached to the arm 11 connects that arm with a rocker arm 14 that is attached to an oscillating shaft 15, whichshaft is actuated by the lead cam 16 through the ig. 4, showing medium of a rack 17 with its cam roll 18 and an oscillating gear 19 fastened to the rocker shalt The rack 17 is aided by the casting 20, at the end. of whici is a collar 21 that supports the end of the rack, and which when taken off permits the removal of the rack. Figs. 3, 4.

The hub of the tool head. 22 has a rack 23 that is also engaged by the oscillating gear 19, and consequently receives its motion from the-lead cam. Fig. 4. The tool head is shown as arranged for receiving the shanks of three tools and for carrying with it one or three spindles. Fig. 21. When the tool head is pushed forwardly by the lead cam and racks and inion, the feed tubes are drawn backward y, which move ment of the feed tubes can be made as long or as short with relation to the movement of the tool head as necessary to produce a screw of the desired length, by ad uSting the sliding trunnion of the connecting rod along the groove 24 of the rocker arm. Figs. 3, 4. When the tool head is drawn back after the end tools have performed their work, the feed tubes are drawn forwardly advancing the rods and exposing a definite length for the next out without the necessity of stopping to ga e the length of the exposed. ends. \Vhether this back and forth motion is communicated to one or all of the feed tubes depends upon whether one or three rolls are placed on the roll disk 9. Figs. 1, 2, 3, 4.

The lead cam 16 is fastened to the cylindrical hub 25 by a bayonet, joint formed by a 'pin 26 sliding in a groove 27. 4, 19, 2

Tochange the amount of the forward movement of the tool head, the cam is turned backward slightl to release the bayonet joint and slide 0 the hub, then another cam having the necessary pitch is substituted and fastened by simply turning, without the use of any tools. This construction provides means which can be manipw lated by any one very uiekly for giving the tool head and the feed tubes the-necessary traverse for long or short screws with short or long threads. To accomplish the fine adjustment so necessary fol-bringing the tool head to exact position, the hub 25 Carry ing the cam is moved longitudinally on the ram shaft 28 to which it is splined, by means of a nut 29 that is threaded on the hub and turns freely. but is held against longitudinal movement on the shaft by a shoulder and the washer 30. Fig. 4.

sprocket wheel 31 attached to the hub of the driving'pulley 32 that is loose on the left hand cnd of the medium of a chain, drives a sprocket wheel 33 that is connected with the gears of :1. speed box 34, thgghgh which a greater or less speed is in rted to a pair .311 bevel gears'iifi, one ofvi'which revolves a shaft 36 cam shaft, through the" closing sleeve is normally thrust forward by wa s f the-g ove 5130f the slerje'will em-f gjt em 71 95 b ce ei n d sefell he J 1 ski-but eollaigand oompel themto-n e .t

having: a worm 37 that meshes with a worm wheel keyed to the cam shaft. 28, which makes one full revolution during each cycle of the machine. Figs. 1, 2, 5. 13.

lnsidc'of each snudle but outside of the feed tube is a chuc tube 39, at the forward end of which is a spring jaw chuck-l0. The position of the chuck with relation to the chuck closing sleeve 41 is determined by the adjustment of the nut 42 threaded upon the rear end of the spindle. Fig. 2. The chuck a spring 43-and is drawn backward for e103: ing the chuck jawsbv levers 44 thatare pivoted in an enlarge part of the spindle and are spread by the conical wedge 45. The wedge is moved backwardly and forwardly at the proper time by the engagement of :1 lug 46 projecting from the collar 4? on the wedge sle ve, with an end-of a lever 48 that is ivotcd to the frame and that is oscillated 3' cams 49 adjustably fastened to the drum 50 which is keyed to the can: shaft. Figs. 2, 13.

If the roll disk 9 has hntone roll attached. so as to more the feed tnbes'one at a time. it will he the roll pointing toward the lever 48, and as each spindle reaches this station. during its revolution with the spinthe head, its chuck is opened and closed, but if three rolls am attached to the roll disk so as to more all of the feed tubes simulta- 'neously, then all the chucks and closed at once.

The inner edge 51 of eachehuck ivedge' collar 41' extends into agroove ln a sleeve 52 that has annular and longitudinalfiroores,

and liesin the center of the 'spin e head encircling the central shaft; but not attached thereto. 'll'hen the feed tubes ate lo, be moved singly, and the chucks opened-end closed one at a time, the screw 53 (F 14) sothat theiedge 51 of the chuck we go collar mores back and forth in a longitudinalfiWOY-eiand i101? cause the sleere to; impartlmetion jromone M chuck wedgecollar to anotherQbut enema; t e feed tubes are-ro e m t d .sim fltanc. gush? the s e i me jnn il theirefl'al' '50 .1 been andb p e ane 11 d3et.,

will he opened the sleeve 52 ijsheld by eating food rod without interfering with its action. It is jouruulod in a bushing in the spindle head and extends through the center of the tool head to the right hand en]. where it: is fixedly supported by a sleeve 61 which carries a driving pulley 62. Figs. 2, 4. lhe rotation of this driving pulley causes the continuous uniform rotation of the spindle; mgardless of their position about the axis of the head.

Encircling the spindle head and fastened thereto in the oil chamber is an annular gear 63 which is in mesh with the pinion 64. Figs. 2. 13. This gear and pinion are so proportioned that one-half revolution of 80 the pinion will revolve the gear, and consequently the 5 indie head, one-sixth of arevolution, \rhi e a full revolution of the pinion will advance the head one-third of a revolution.

Keyed to the hub of the driving pulley 3:? on the (am shaft :28 next to the sprocket wheel 31 is a sprocket wheel 65. This Sprocket wheel drives a chain that passes around a sprocketwheel 66 that turns on the shaft 67 which carries the spindle rototing pinion 64. Figs. 5 6.

Vithin and attached to the hub of the sprocket wheel 6 is a ratchet-plate 6S and encircling an enlar ed part of 'lthe shaft Gland adapted to side thereon, but coinpelletl' to rotate therewith is :a' block 69. '1 This block carries v] bolts SSW-shaped to ongagethc notjc les of the rntchetfGS towardwhich they are" nominally by 190. springs J0; Figs, '6, 8,,9. rArra d-jto 1 preventthe engagement-of the pair 5 with he ratthet exceptnt the fpropertimeyis'ga. f? lever- 71 which normally is in suchw-p'osi- 'tion. that. thejcam surface 72 T'forcesjthe 105 block carrying the. pairls :back against the rese'ure 'oi :t-he' "springs; Figs. 76, 7, 26. .1 Iounted upon thecan Shaft near the driia ingpuileynndrotat in .thereurithlis acam Y .Ttleomposedzof two' ciisks which are held iljlQ 9 et er. rh tan h e'ae eetr a justnient'with relatiou other." f

" flhe outer. edge of eaeh :eam

polling the lever 71 to return to its normal position where the cam surface 72 engages with the pawls and pulls them out of engagement with the ratchet. To have the spindle head move onc-third of a revolution the cam disks are adiusted so as to lengthen the depression and hold the lever out of its normal position until just before the pinion has made one full revolution. Figs. 2, 5, 6, 7, 8, 9. A modification of this construction is shown in Figs. 10, 11, and 26 where the lpawls 144 and cam surfaces 145 are integra with the sliding block 146, and the lever 147 has but a. simple Fin 148 for engaging the cam surfaces. his is the preferred construction as it has the advantage of fewer parts. By this mechanism the spindle head can be rotated so as to stop at six or three stations and present the rods to either six or only three tools.

Fastened about the spindle head is an indexing ring 75 with teeth on its periphcry. This ring is in the form of an annular rack and it may have its teeth out by an ordinary gear cutter. Sliding vertically on the end of the s indle head frame is an index bolt 76 that as its up or and provided with teeth shaped to t closely in three of the spaces between the teeth of the annular index rack and hold the spindle head rigidly during the cutting action of the tools. Fi 2, 5, 12.

Keyed to e cam shaftand revolving therewith is athree part cam consisting of an intermediate disk 7? and two outside disks 78 and 79, fastened together by bolts, which when loosened allow concentric udiustment of the disks with relation to each other. F i s. 2, I2.

Attached to the index bolt 76 is a stud 80 which is engaged by the projections 81 on the two cam disks 5'7 and 78 (Fig. 12) whereby at the proper time the bolt is withdrawn from engagement with the indexing rack and the spindle head left free to be revolved. The outer cam surface formed by the pro'ections 81 is made longer or shorter by t e adjustment of the cam disks T7 and 78 with ielation to each other, for the purpose of keeping the index bolt out of contact with the indexing rack a longer or shorter time corresponding to the setting of the rerolrin mechanisms for turnin the spindle heag onesthird or onesixth o a revolution.

Upon the completion of the periodic rotatory movement of the spindle head the stud 80- disengages from the rejections, Off thecam disksnndthe 6O mashe sp the sole is,

the-finder bolt b 1 on the 'fram lLh-s and; the: index co h 1 rack; J il ,,h-

the cam disk 79 )asses under the roll 84 mounted on the in ex bolt and prevents any loosening of the bolt until the tools have ceased to not upon the rods, and a new presentation is to be made. Figs. 2, 5, 12.

On the face of the frame is a radial tool box 85 the hub of which is fastened in an opening in the frame, Figs. 1, 16 17.

In the box is a holder 86 that 15 arranged to be moved radial] toward and from the adjacent spindle. he tool holder carries a cutting tool 87 of the desired form. Attached to the tool holder is a rack 88 and extending through the hub of the tool box is :1 shaft 89 with a pinion 90, keyed thereto and engaging with the rack. Fig. 16. Splined upon the shaft is a pinion 91 that engages teeth on the upper end of a vertical rack 92. Fig. 15.

Adjustably attached to the cam shaft is a cam 93 which on ages a roller 94 mounted on a yoke 95 whic is fastened to the up right rack. A spring 96 tends to lift the upright rack and cause it to rotate the pinions in such manner as to withdraw the cutting tool quickly from its work. At the pro r time the cam draws the rack downwardly and causes it to rotate the pinions so as to feed the tools slowly and evenly toward the work. F' 2, 15.

Below ife radial tool holder on a cross slide frame 97 is a front tool ho1der-98 and a. rear tool holder 99, each of which holders carries a cutti tool 980, 990. 17. Rotating in .the odv of the slide frame is a shaft 100 inctuated by a spiral gear 101 that meshes with a s iral gear 102 fasten on the cam shaft. lgs. 1, 2, 17.

On the ends of the transverse slide shaft; and adjustably fastened to hubs 1003 thereon by screws 1004 are cams 103 which act upon rolls 104 suspended from the tool holders and give the necessary forward and backward movements to the cutting tool holders. A rtion of each cam carrying hub is three ed to receive an adjusting nut 105 whereby fine adjustment to re the exact amount of advance of the too 5 can be madewithout disturbing the clamping bolts which hold the tools in the holders. Fur thel'moreholes 106' are cutin the cam hubs sothnt therelative positions ofthe cam surfaces may be chan ed with relation to the revolutions of the shafts by slip ing the pin 10? in one or the other of the holes. Fig-17.

Mounted n n-linement-avi the upper giindle station -is a tool spindle 108jthnt is u a in the direction of its 'btlt islilw vented :fro1n=; 1revo]ution by the plate "109 which-itjbears. Fig. 4.

t eaded: massi e. flan ednut-@11 re p d mi til selyi n were the tony- 0i. the earmawher by ns-m1;

t0 111love" ends of the other rod 'spindle is drawn forward and pushed back by the reciprocating movement of the head. v

l igs. 3, 4.

lVhen there is but one roll on the roll disk and the feed tubes are being operated one at a time. it will he the one toward the elint'ltmg lerer and on the front side of the n chine. -Direrttly after Flint-king the time at'- rives for the periodic rotatory movement of the spindle head which brings a new reddirertly opposite the tool spindle and read for the roughing out. the tool head ad raneea drawing the tool spindle with it, all the strains of the roughing cut are resisted by the tool spindle alone and are not cominnnieated to the other tools :ariied by the head which are simultaneously performing the more accurate finishing Cttts on the pin 111, sliding in the bnshin r 112 prevents any rotatory move ment of tie tool heat as it advances and withdraws the tools. -ig. t.

Rotating in the tool head frame in longitudinal alinement with the two side rod spindles are two threading spindles 113.

' These spindles may carry taps or dies, or

' ment to the spindle in one direction through i a roller clutc one may carry a tap and the other a die, according to the work which it is desired to aecom )lish. Fi s. 21, 22. Sliding on each threa tug spirit le, but rotatably fastened thereto by screws 114; is a friction clutch hub 115. Loose on the spindle is the long hub 115!) of a )inion 1.16. This pinion and its hub has no longitudinal movemenhbeing held by the frame, and it communicates its move- 1 117 ofeommon form that has its n:ale part keyed on the spindle so as to en age with the female part in the interior we 1 of the hub of-the pinion. Figs. 22, 21. In front of the frietion cluteh hub is a gorresponding frietion cup -forniod in a part of a oo ely running gear 118 that is held by the frame and surrounds the spindle. Meshing with this gear is a pinion 119 mounted it mn a shaft 120 which extends back to a pinion 121 that meshes with the spindle rotatin pinion 116. Fig. "The supporting s eeve il. ('arryiug the driuing pulley (i2 and tubular drivingshaft 56, has teeth tltt) out in its surface which mesh with the teeth of the pinion 116. Figs. 4, 19.

Held by the tool head frame parallel with each threading spindle is a min-rotating sliding shaft IQQ'that is drawn forwardl by a spring 123. Mounted upon each 811' ing shaft is a forked arm 124 which fits a groove in the friction clutch hub 115 and effects its longitudinal movement.

On each side of the frame of the tool head engages a stud on the adjacent slide shaft 122. A -transwn'sely extending shaft. 129 revolved by spiral gears 130 controls the movement 1. of these levers through the medium of the earn disks 131, attached bv bolts to hubs 132 l fastened to the shaft. Figs. 3.1, 15%.

The die eollet 133 provided with a die is wet forward to approach the work to be threaded by adj listing the follower 134 through the medium of the threaded rod 135 and the nut; 136 whieh is eonneeted with the tube .137 that. may be turned by a key 138 a lied at the right. hand end. Figs. 18, 22. \ilien the proper time for threadiiig comes the cam disk 13] allows the lever 128 to drop and the spring 123 to presa the die against the work and start the cutting, after which the tool follows the thread it cuts. Atthis time the finger 12.? engages the cam disk 12-6 and )revents further movement of the frietion elntch hub until the required length of thread is out. then the finger 125 drops oi? the ram surface and allows the friction eluteh parts to be thrown together by the spring. which causes the spint le to be given a faster rotation. This motion imparted through the friction clutch being faster than the speed of the rodspindle causes the die to be nnserewed from the rods. soon as the diehas unscrewed from the thread it has cut; the spring 151 encircling the adjustin Y tube 137 draws the die away from the PM When the friction clutehparts are engaged thethreading tool spindles are rotated faster than the rod spindles so that the tools will he nnaerewed from the rods. but at all other times the tln'eading tool spindles are rotated slower than the rods so that threads will be eut thereon. "The roller clutch between the driving pinion and the threading tool spindle permits the increase of speed automatically.

'lq permit the disengagement of the hi h speed gearing when the threading spind es are not to be used for threading, the bearing boxes 139 for the shafts 120 are pivoted to tbeframe by bolts 140 so that they canbe turned and the pinions lifted out of mesh and thus held by the springs 1451, which likewise must be made to retain the boxes with the gears in mesh when lowered to the pro )er notch of the latches 142. F ig. 20.

linden circumstances calling for one or both of the threading tool spindles to be used as box or other tool holders, a nut 110,

similar to the nut on the upper tool holder,

sliding shaft there is also a [tr gger 125. the flange that. fits the groove in the end of the forward end of which is held against the veripheral surface of a disk 126 that is ad ]uStably attached to a hub 127 whieh is fastened to the oscillating pinion shaft 15. Figsfl, 19. A lerer 128 pivoted on each tool head so the spindle will be carried back and forth with the tool head as previously desrribed.

the groove provided for the die follower l rolls 1530 to prevent rotary internment! ofthe A screw 14.9 is turned down into.

spindle, and the withdrawal of the screws ll-"l in the friction clutch hub releases the die feeding mechanism. Fig. 23.

In the machine illustrated three rods of stock can be intermittently fed to the tools. When the feeding and chucking mechanisms are adjusted in one manner the three rods of stock will he unclasped, fed forward and clamped simultaneously, so that each rod will be acted upon by its own. tool and these tools may be similar or dissimilar in char acter. I E the chucking and feed mecl'ianisms are adjusted in. the other manner, the three rods of stock are released, fed and clamped successively, so that each rod can be presented progressively to all of the tools which are required to produce the desired cuts. i

If the spindle head rotating and indexing mechanisms are in one adjustment, the spin dle head is moved one-sixth of a revolution each time the index bolt is withdrawn so that the stock held by the spindles may be presented to six end tools. if the spindle head rotating and indexing mechanisms are in another adjustment, the spindle head'is moved ouethird of a revolution each time the index bolt is Withdrawn, and thus presents each piece of stock carried by the spindies to three end tools.

In the tool holding and resenting mechanisms a variety of combmations may be fornwcl with thread cutting spindles or with the thread cutting spindles changed to tool spindles which are independently adjustable and arc'advanced simultaneously with the tool head.

The lead cam mechanism provides for an instant: change of cams having different pitches, and eliminates a source of great delay in altering the machine so that it will accomplish ditfercnt kinds of Work. With the construction illustrated and described these adjustments can be quickly and accurately made by any ordinary mechanic with out anger of'injuring the machine or spoiling or wasting stock. Long or short sections of rod can be fed and Ion or short portions threaded as desired an the rods are fed close to their ends so that there is very small waste when the ends are reached.

The spindle gears, which in prior machines owing to their high speed wear out quickly, in this machine run ina reservoir of oil, which oil at the same time luhricates the hearings so that the parts wear a long time. The threading spindles and the roughing tool spindle are independent of the tool slide so that the exterior cutting tools do not interfere with each other nor does the distortion of one by undue strains affect any other.

The indexing of the spindle head is positive and the locking mechanism is sure and is made in such manner that it is accurate and will operate ll lou tlme Without an prcciable wear, and shoud. the teeth become somewhat worn, the indcxlug rlng or an nular rack can be turned to another position so that its teeth and the teeth of the index bolt will engage in a relatively different position. The interlocking tccth of the index mechanism are so cut as to overcome the strain caused by the ventral drive shill in revolving the head and the rod spindles.

The lead c'alu cannot only he removed and another :mhsliluted very quickly, but it is capable of very accurate adjustn'wut. The (llt' starting cams are quickly adjusted and are positively operated while the lovers hold the side rods back until the dies are ready to start on the stock. The roller clutches which arcprokidcd for causing the rotation of the threading spindles can be changed and used either right handed or left handed it required. The side radial tool slides are actuated by mechanisms which have but little Wear, and which are positi e in their action. And the slide cams can be fastened so they may be quickly rclIlUHtl and others substituted in the same manner as the lead cum. 7

The invention claimed is: '1. In a. screw machine in combination, a rotatable spindle head, rotatory spindles mounted in the head, a feed tube movable lonqitudimllly in each sJindle, a longitudi nall movable feed shat t extending axially through the spindle head,

studs reiuovably mounted upon and. movable with the feed shaft and adapted to engage and more the feed tubes, and means for reciprocating the feed shaft, :mhstantially as specified.

2. In a screw machine in combination a spindle head, a spindle mounted in the head, a feed tube nlovahle longitudinally in the spindle, a longitudinally inlovahle feed Shaft extending axially through the s rindlc head, means mounted upon thG fLBKi shaft'and adapted to engage and move the feed tube, a rocker arm. means for oscillating said arm, and an adjustahle connection between said arm and. the feed shaft, substantially as specified.

3. In a screw machine in combination, a spindle. a feed tube movable longitudinally in the spindle, a longitudinally movable food shalil, means mounted upon the feed shaft and adapted to engage and move the Feed tube, a rocker arm, a connection between the feed shaft and the rocker arm, an oscillating gear for rocking said arm, a rack for oscillating said gear, a. removable can] for reciprocating the rack and means for ro lnting the cam, substantially as specified.

4. ln a screw machine in combination, a spindle, a feed tube movable longitudinally in the spindle, a longitudinally movable feed shaft, means mounted upon the feed shaft and adapted to engage and more the feed 

